Converting type DataRow to Control

[gregburningham]

Hi

I have some code where I read a list of data items from a DataTable. Each of these rows although stored as a string is also a Control on my page. I would therefore like to convert the row.column returned from my loop into a Control that I can set properties on (such as enabled=true) etc.

Unfortunately I am getting an "Invalid Cast" error when I execute the following code ....



While vRowCount < vDataTable.Rows.Count
vDataRow = vDataTable.Rows(vRowCount)
lblMessage.Text = lblMessage.Text & vDataRow(&quot;UpdateAllowed&quot
If vDataRow(&quot;UpdateAllowed&quot.ToString = &quot;Y&quot; Then
lblMessage.Text = lblMessage.Text & &quot;UPD!&quot;

vControl = CType(vDataRow(&quot;ItemName&quot, DropDownList)
vControl.Enabled = True
End If
vRowCount = vRowCount + 1
End While

Please can someone advise me on where I am going wrong ?

Thanks in advance

Greg B

 

[Paszt]

CType Function - Returns the result of explicitly converting an expression to a specified data type, object, structure, class, or interface.

CType(expression, typename)
expression - Any valid expression. If the value of expression is outside the range allowed by typename, an error occurs.
typename - Any expression that is legal within an As clause in a Dim statement, that is, the name of any data type, object, structure, class, or interface.

You are trying to convert a string (returned by 'vDataRow(&quot;ItemName&quot') to a DropDownList which is not possible.

I'm not exactly sure what it is you're trying to accomplish?

If you want to add a new DropDownList:

Dim vControl As System.Web.UI.WebControls.DropDownList
vControl = New System.Web.UI.WebControls.DropDownList()
vControl.ID = vDataRow("ItemName")
Me.FindControl("Form1").Controls.Add(vControl)

-Stephen Paszt
_________________________________________________

Man usually avoids attributing cleverness to somebody else
- unless it is an enemy. -- Albert Einstein

 

[gregburningham]

Thanks for the advice what I am actually doing is the following:

I am returning a text string eg. &quot;ManagerDropDownList&quot; from my table

I then want to compare this text string with any controls (ID's) on the form to see if a control with a corresponding ID exists - then I will set that controls property ...

 

[Paszt]

Oh, I see. Try this:

Dim wctrl As System.Web.UI.WebControls.WebControl
For Each wctrl In Me.FindControl("Form1").Controls
    If wctrl.ID = vDataRow("ItemName") Then
        'set controls properties
    End If
Next

-Stephen Paszt
____________________________________________________
&quot;God does not care about our mathematical difficulties. He integrates empirically.&quot; -- Albert Einstein